With the rapid development of the flat panel display technology, an Organic Light Emitting Display (OLED for short) has more and more applications due to its excellent characteristics such as self-luminescence, high brightness, wide viewing angle, and rapid response.
In order to drive an organic light-emitting device in the OLED to emit light, the organic light-emitting display panel includes an emission driving circuit. The emission driving circuit includes a plurality of cascaded shift registers, and the circuit structure of the shift register and the corresponding operating sequence are shown in FIGS. 1 and 2. FIG. 1 is a circuit structure diagram of a shift register provided in the related art, and FIG. 2 is an operating sequence diagram of a shift register provided in the related art.
In view of the current demand for the display effect of the organic light emitting display panel, it is needed to use a dimming mode in driving the organic light emitting device to emit light. In the dimming mode, an input signal provided at an input signal terminal IN is at high level for a longer duration, as compared with the normal display. When the shift register in the related art has a circuit structure as shown in FIG. 1, the input signal is at high level for a longer duration, such that the node N4 of the control node N2 would be suspended for a long time. In this case, the transistor T3 cannot be switched on, the level of the node N2 cannot be effectively controlled, and the shift register cannot operate normally.